<!DOCTYPE html>
<html>

	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>

	<body>
		<script type="text/javascript">
			var a = 3;
			var b = 4;
			swap(a, b);

			function swap(a1, b1) {
				temp = 0;
				temp = a1;
				a1 = b1;
				b1 = temp;
				
				
			}

			console.log(a + "," + b)
		</script>
	</body>

</html>